Diacyloxy-nitrostilbenes



United States Patent 3,406,194 DIACYLOXY-NITROSTILBENES Myron S. Simon, Newton Center, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed May 25, 1964, Ser. No. 370,066 Claims. (Cl. 260-479) ABSTRACT OF THE DISCLOSURE Novel diacyloXy-nitrostilbenes which are useful intermediates in the preparation of silver halide developing agents and dye developers (dyes which are also silver halide developing agents).

This invention relates to novel chemical compounds and more particularly to novel diacyloxy-nitrostilbenes.

A primary object of this invention therefore is to prepare novel diacyloxy-nitrostilhenes which are useful intermediates in the preparation of silver halide developing agents and dye developers (dyes which are also silver halide developing agents).

Another object is to provide a novel process for preparing the aforementioned compounds.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.

The diacyloxy-nitrostilbenes to which this invention is directed may be represented by the following formula:

wherein Y is a para-diacyloxy or an ortho-diacyloxy phenyl group, which group may also be substituted by alkyl and halogen groups; Ar is an aryl nucleus such as a benzene or naphthalene nucleus; each Z is an alkyl group, preferably a lower alkyl group of not more than five carbons, such as methyl or ethyl, or a halogen, such as chlorine; rt is a positive integer from 1 to 5, inclusive; and m is a positive integer from 1 to 2, inclusive; at least one of said NO groups being in one of the ortho and/or para positions with respect to the CH=CH group.

By the term acyloxy is meant the grouping RCOO- wherein R is an aliphatic group, preferably containing one to five carbons, i.e., the acyloxy group is an acetoxy group, or R may be an aryl or aralkyl group, e.g., benzoyl group; hence, the acyloxy group would then be a benzoXy roup. g As examples of novel compounds within the scope of this invention, mention may be made of the following 1) oooom (I) C O CH: 2,5 -diacetoxy-4-nitrostilbene c CC ( 0C OCH:

0 0 CH3 2,S-diacetoxy-4-methyl-4'-nitrostilbene ornoooUonamQ- -3 ,4-diacetoxy-4'-nitro stilbene 0 G O 0 Ha 0 c 0 B: 2,5-diacertoxy-2-nitrostilbene o 0 CH5 4-(2,5-diacetoxy-phenethenylene)-1-nitronaphthalene (IJCOCHa O C O C Ha 2,5 -diacetoxy-2',4-dinitrostilbene (i)COCH:

GH=C BBQ-N0, OH NO:

0 C 0 0 H3 2,5 -diacetoxy-4-methy l-3',4'edinitrostilbene 9) C H30 C 0-- 3,4-diacetoxy-2',4-dinitrostilbene O C O CH; N02

NO: I

OCOCH:

2,5-diacetoxy-3,4-dimethyI-Z',6'-dinitrostilbene 2,5-diacetoXy-3'-rnethyl-4'-nitrostilbene The novel compounds of this invention may be prepared by reacting a compound of the formula:

wherein Y is an orthoor para-dihydroxy phenyl group, which group may also be substituted by alkyl or halogen groups; with an acyl halide, preferably acetyl chloride, or a benzoyl halide, preferably benzoyl chloride, and an acid, e.g., concentrated sulfuric acid, to form the desired compound of Formula (A).

As examples of useful compounds within the scope of Formula (B), mention may be made of the following:

2,5 -dihydroxy-4'-nitrostilbene 2,5 -dihydroxy-4-meithyl-4'-nitrostilbene 3,4-dihydroxy-4'-nitrostilbene 2,5 -dihydroxy-3,4-dimethyl-4-nitrostilbene I OH.

2,5-dihydroxy-2nitrostilbene qekwgm 4-(2,S'-dihydroxy-phenethylene)-l-nitronaphthalene 2,S-dihydroXy-24'-dinitrostilbene 2,5 -dihydroxy-4-methyl-3,4'-d-initrostilbene HO OH=CH HO N02 3,4-dihydroxy-2,4'-dinitrostilbene 0113- C H=CH CH3 N02 2,5-dihydroxy-3,4-dimethyll-2',6'-dinitrostilbene OH 4-chloro-2,5-dihydroxy-4'-nitrostilbene (12a) OH 0 a CH=CH NO:

OH 2,5 -dihydroxy-3 '-methyl4'-nitrostilbene Compounds of Formula (B) are described and claimed in the copending application of Warren E. Solodar, Ser. No. 370,041, filed concurrently, now US. Patent No. 3,232,995. As disclosed therein, these compounds, e.g., Compounds 1a-12a, may be prepared by reacting a compound of the formula:

( YL-CH=CHAI wherein Y is a para-dialkoxy or an ortho-dialkoxy phenyl group, which group may also be substituted by alkyl or halogen groups, with an amine hydrohalide dealkylating agent, such as methylamine hydrohalide, dimethylarnine hydrohalide, trimethylamine hydrohalide, ethylamine hydrohalide, ethanolamine hydrohalide, pyridine hydrohalide, quinoline hydrohalide, diphenylamine hydrohalide, aniline hydrochloride, aniline hydrobromide and aniline hydrofluoride. In combination with the heretofore-mentioned dealkylating agents, the passage of dry hydrogen chloride gas through the reaction mixture facilitates the reaction in the temperature range of ISO-200 C. (For general discussion in the use of aliphatic, aromatic and heterocyclic amine hydrohalides as dealkylating agents, see The Cleavage of Ethers by Robert L. Buswell, Jr., Chemical Reviews, Volume 54, 1954, pan ticularly pages 635-636.)

The novel compounds to which this invention is directed are useful intermediates in the preparation of aminoaralkyl-diacyloxy-substituted benzenes, as disclosed in the aforementioned copending application of Warren E.'

Solodar, U.S. Patent No. 3,232,995.

The latter compounds in turn have heretofore been found to be useful as intermediates in preparing both dye developers (dyes which are also silver halide developing agents and which are employed in color photography) and silver halide developing agents. The preparation of p-(2,5-diacetoxyphenethyl)-aniline hydrochloride is dis closed, for example, in U.S. Patent No. 3,019,254, issued to Milton Green et al. on Jan. 30, 1962.

The following examples show by way of illustration and not by way of limitation the practice of this invention.

Example 1.Preparation of 2,5-dimethoxy- 4'-nitrostilbene A mixture of 24.5 gm. of p-nitrophenyl acetic acid (0.135 M), 18.0 gm. of 2,5-dimethoxy benzaldehyde (0.108 M), and 6 ml. of piperidine was refluxed with stirring at 130 C. for 3.5 hours. The piperidine was distilled off and the temperature was raised to 160 C. for 3 hours. The mixture, on cooling, was diluted with 25 ml. of acetic acid, and then poured into 125 ml. of water. A dark red oil separated. The supernatant liquid was decanted and the residual oil solidified on treatment with 25 ml. of ethanol. The solid was filtered off and recrystallized from 300 ml. of ethanol, to give 11.5 gm. of yellow needles which melted at 115-116 C. A recrystallized sample melted at 116.5-117 C., and gave the following analysis.

Calculated: C, 67.4; H, 5.3; N, 4.9. Found: C, 67.4; H, 5.5; N, 4.9.

It will be appreciated that other useful compounds within the scope of Formulae (A) and (B) where m is 1, e.g., 2,5-dimethoxy-4-methyl-4'-nitrostilbene, 3,4-dimethoxy-4-nitrostilbene, 2,5 dimethoxy-3,4-dimethyl-4- nitrostilbene, etc., may be prepared utilizing the procedure set forth in Example 1, i.e., by substituting the appropriate reactants and proper amounts of each reactant, e.g., 2,5-dimethoxy-4-methyl benzaldehyde would replace 2,5-dimethoxy benzaldehyde to form 2,5-dimethoxy-4- methyl-4'-nitrostilbene, followed by dealkylation.

Example 2.Preparation of 2,5-dihydroxy- 4'-nitrostilbene A mixture of 8.55 gm. (0.03 M) of 2,5-dimethoxy-4'- nitrostilbene (prepared as described in Example 1) and approximately 40 gm. of pyridine hydrochloride was heated at bath temperature of 205-212 C. for half an hour. The reaction mixture was allowed to cool slightly, then was poured into water. A tan precipitate separated and was filtered off, washed with water, and desiccated in vacuum over P The resulting dried crude product was recrystallized from 125 ml. of anisole, after filtering ofl some insoluble tar, to yield 4.5 gm. of yellow crystals which melted at 231-235 C., and which analyzed as follows.

Calculated: C, 65.4; H, 4.3; N, 5.4. Found: C, 65.2; H, 4.3; N, 5.3.

Example 3.Preparation of 2,5-diacetoxy-4'-nitrostilbene A mixture of 4.0 gm. of 2,5-dihydroxy-4'-nitrostilbene (prepared as described in Example 2), 40 ml. of acetyl chloride and 4 drops of concentrated H SO was refluxed for one and one-half hours. The starting material went into solution with evolution of HCl. During the latter part of this reaction, a bright yellow solid separated. Excess acetyl chloride was evaporated in vacuum. The residue was treated with water, filtered and desiccated in vacuum over KOH. The resulting dried crude product was recrystallized from 350 ml. of n-propyl alcohol to yield 3 gm. of bright yellow fibrous crystals which melted at 192-194 C., and which gave the following analysis.

Calculated: C, 63.3; H, 4.4; N, 4.1. Found: C, 63.1; H, 4.4; N, 4.1.

Example 4.Preparation of p-(2,5-diacetoxy-phenethyl)- aniline hydrochloride An incomplete solution of 3.1 gm. (0.0091 M) of 2,5- diacetoxy-4'-nitrostilbene (prepared as described in Example 3) in ml. of ethyl acetate containing 3 gm. of 10% Pd/BaSO was hydrogenated in a Parr shaker. Hydrogen uptake was complete in three minutes.-The catalyst was filtered off, and 0.78 ml. of concentrated HCl (0.0095 M) was added to the clear, colorless filtrate. On seeding and scratching, a fibrous white precipitate separated. This precipitate was filtered 01f, washed with ethyl acetate, then ether and air-dried to yield 2.8 gm. of the desired product which melted at 154-158 C., and gave the following analysis.

Calculated: C, 61.8; H, 5.8; N, 4.0. Found: C, 62.0; H, 5.9; N, 3.6.

Example 5.Preparation of 2,5-dimethoxy-2',4- dinitrostilbene To a warm (50 C.) mixture of 30.0 gm. of 2,5-dimethoxy benzaldehyde (0.18 M), 40.8 gm. of 2,4-dinitrophenyl acetic acid (0.18 M) and 200 ml. of ethanol, 24 ml. of piperidine was slowly added while stirring. Some cooling was necessary as the piperidine was added to the reaction mixture. Gas and heat were evolved from the deepening yellow reaction mixture. The resulting mixture was refluxed with stirring on the steambath for two hours. A precipitate formed after refluxing for 15 minutes. The mixture, on cooling, was filtered and the precipitate was washed with ethanol and then desiccated in vacuum over P 0 to yield 36.0 gm. (60.5% yield) of orange needles which melted at 171-173 C., and which gave the following analysis.

Calculated: C, 58.2; H, 4.3; N, 8.5. Found: C, 58.0; H, 4.3; N, 8.5.

It will be appreciated that other useful compounds within the scope of Formulae (A) and (B) where m is 2, e.g., 2,5-dimethoxy-4-methyl3',4-dinitrostilbene, 3,4- dimethoxy 2,4 dinitrostilbene, 2,5 dimethoxy-3,4-dimethyl-2',6'-dinitrostilbene, etc., may be prepared utilizing the procedure set forth in Example 5, by selecting the appropriate reactants and proper amounts of each reactant, e.g., 2,5 dimethoxy-4-methyl benzaldehyde Would replace 2,5-dimethoxy benzaldehyde and 3,4-dinitrophenyl acetic acid would replace 2,4-dinitrophenyl acetic acid to form 2,5-dimethoxy-4-methyl-3,4-dinitrostilbene, fol lowed by dealkylation.

Example 6.-Preparation of 2,5-dihydroxy-2,4'- dinitrostilbene A mixture of 6.0 gm. of 2,5-dimethoxy-Z',4-dinitrostilbene (prepared as described in Example 5) and 20 gm. of pyridine hydrochloride was refluxed under nitrogen with stirring for half and hour at bath temperature of 220 C. The hot reaction mixture was poured into 200 ml. of warm dilute HCl and a gummy light-brown pre- =cipitate formed which soon solidified. The brown solid that separated was filtered off, washed with water and desiccated in vacuum over P 0 to yield 5.5 gm. of rust colored solid which melted at 205-220 C. The resulting dried crude product was recrystallized from 150 ml. of o-dichlorobenzene to yield 1.85 gm. of orange crystals 7 which melted at 248-251" C., and gave the following analysis.

Calculated: C, 55.6; H, 3.3; N, 9.2. Found: C, 55.6; H, 3.2; N, 9.1.

Example 7.-Preparation of 2,5-diacetoxy-2,4- dinitrostilbene A mixture of 4.0 gm. of 2,5-dihydroxy-2',4'-dinitrostilbene (prepared as described in Example 6), 40 ml.'of acetyl chloride and 4 drops of concentrated H 80 was refluxed for :4 hour. The starting material went into solution with evolution of HCl. The resulting mixture was cautiously poured into 250 ml. of ice water. A yellow precipitate formed which was then filtered, washed with water and desiccated in vacuum over KOH, to yield 3.3 gm. of yellow solid which melted at 172-190 C. The resulting crude product was recrystallized from 40 ml. of acetic acid to yield 1.6 gm. of yellow needles which melted at 194-197 C., and gave the following analysis.

Calculated: C, 56.0; H, 3.6; N, 7.2. Found: C, 55.7; H, 3.7; N, 7.2.

Example 8.Preparation of 2',4'-diaminophenethyl- 2,5-diacetoxy-benzene hydrochloride A mixture of 2.05 gm. of 2,5 diacetoxy 2',4 dinitrostilbene (prepared as described in Example 7) in 100 ml. of methyl cellosolve containing 1.0 gm. of 10% Pd/ BaSO was hydrogenated in a Parr shaker. Hydrogen uptake was complete in ten minutes. The catalyst was filtered off, and 1.0 ml. of concentrated l-lCl was added to the pale yellow filtrate. The filtrate was then diluted with 400' ml. of dry ether. There was a slow separation of oil, which soon solidified. The resulting solid was filtered and then desiccated in vacuum over P and KOH, to yield 1.6 gm. of white solid which melted at ISO-188 C., and gave the following analysis.

Calculated: C, 54.0; H, 5.5; N, 7.0; Cl, 17.7. Found: C, 53.8; H, 5.4; N, 6.6; Cl, 16.9.

Since certain changes may be made in the above process and product without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is: 1. A compound of the formula:

Y-CH=CHArZ I (N01)!!! wherein Ar is an aryl nucleus selected from the class consisting of benzene and naphthalene nuclei; m is an integer from 1 to 2, inclusive; each Z is selected from the group consisting of halogen and alkyl groups; n is an integer from 1 to 5, inclusive; Y is selected fromthe group consisting of para-diacyloxy phenyl, ortho-diacyloxy phenyl and alkyl and halogen substituted derivatives thereof; said acyloxy groups being represented by:

RCO

wherein R is selected from the group consisting of saturated aliphatic hydrocarbons containing from one to five carbon atoms and phenyl; at least one of said NO groups being in one of the ortho and para positions with respect to --CH==CH. v

2. A compound as defined in claim 1 wherein Ar is a benzene nucleus.

3. A compound as defined in claim 1 wherein R is CH 4. 2,5-diacetoxy-4-nitrostilbene.

5. 2,5-diacetoxy-2',4'-dinitrostilbene.

References Cited UNITED STATES PATENTS 3,019,254 1/1962 Green ct a1. 260479 LORRAINE A. WEINBERGER, Primary Examiner.

M. G. BERGER, Assistant Examiner. 

